The National Adult Literacy Survey of 1992 alerted educators and policymakers to a previously underrecognized problem: nearly one-fourth of the American adult population is functionally illiterate.1 More recently, the medical community has become aware of the prevalence of inadequate health literacy, or the inability to comprehend written material in a health care setting. In 1 study involving more than 2500 patients in 2 urban hospitals, 42% of subjects could not understand written instructions for taking medication on an empty stomach.2 Importantly, functional health literacy is lower in older age cohorts in the United States.3 In a sample of English-speaking adults aged 60 years and older, less than 20% demonstrated adequate health literacy skills.2 The age-related decline in health literacy skills persists even when cognitive function is taken into account.3 Although educational attainment and literacy are not interchangeable, the 2 concepts are closely related (average reading skills are generally 3-5 grade levels lower than the last year of school completed). The US Census Bureau data from 2007 reveal that 86% of Americans aged 18 to 74 years identify themselves as high school graduates compared with only 73% of Americans aged 75 years and older.4 Societal constraints on educational attainment may help explain this discrepancy. A child aged 14 years in 1936 in the middle of the Great Depression may not have had the opportunity to complete high school. That same child would have been aged 85 years in 2007.
Muir KW, Lee PP. Literacy and Informed ConsentA Case for Literacy Screening in Glaucoma Research. Arch Ophthalmol. 2009;127(5):698-699. doi:10.1001/archophthalmol.2009.59